Incident commanders (IC's) manage firefighters as teams rather than individuals in order to manage complexity and ensure firefighter safety. These teams are typically defined by the engine or the vehicle the firefighter has been assigned to. During firefighter operations, firefighters are taught to remain in close proximity to other team members to prevent firefighters from becoming isolated from the team, particularly when visibility is reduced by smoke and debris. If a team has been assigned to a specific firefighting task or zone of the incident location (e.g., venting a roof, search and rescue, advancing on a specific side of a building, etc.) and the IC has not heard about any emergencies from the team leader or any of the members of the team, the fire chief may assume the team is in a specific location and progressing as instructed and that no additional action, resources, or emergency response personnel is required. However, a firefighter becoming separated from the team either accidentally (such as, for example, falling through a floor of a burning structure or becoming isolated when a ceiling of the building collapses) or intentionally (e.g., when a firefighter remains behind the team or starts off away from the team intentionally), represents a high risk situation that requires immediate response. Such situations are difficult to prevent and predict, and responding to such situations can place other emergency personnel at risk. Likewise, even if emergency personnel are in close proximity to their team, the complexity and confusion of emergency response incidents can make it difficult to determine when a particular firefighter or the like is in distress, is experiencing undesirable health impacts, and/or is at risk of health impacts.
Since physical proximity of the members of a team to each other is often more significant than having the precise location of each firefighter, there is a need for systems that can monitor the relative proximity of the firefighters to each other as an indication of firefighter safety, and/or monitor firefighter health characteristics and alert the IC to firefighters at risk.